For the streaming of a sound (or sound field) representation over a transmission channel with time-varying conditions, layered coding is a means to adapt the quality of the received sound representation to the transmission conditions, and in particular to avoid undesired signal dropouts.
For layered coding, the sound (or sound field) representation is usually subdivided into a high priority base layer of a relatively small size and additional enhancement layers with decremental priorities and arbitrary sizes. Each enhancement layer is typically assumed to contain incremental information to complement that of all lower layers in order to improve the quality of the sound (or sound field) representation. The amount of error protection for the transmission of individual layers is controlled based on their priority. In particular, the base layer is provided with a high error protection, which is reasonable and affordable due to its low size.
However, there is a need for layered coding schemes for (extended versions of) special types of compressed representations of sound or sound fields, such as, for example, compressed HOA sound or sound field representations.
The present document addresses the above issues. In particular, methods and encoders/decoders for layered coding of compressed sound or sound field representations are described.